This invention relates to the confinement of plasmas by magnetic fields and, more particularly, to a device which in its preferred embodiment is a hybridization of two prior devices commonly known as the tokamak and the torsatron.
The underlying principle of all types of magnetic plasma containment devices is the containment of a hot dense ionized gas away from physical walls for a time sufficient to allow fusion reactions to occur. Devices employed for the containment of plasmas by magnetic fields may have various configurations. One well known type of such devices is the toroidal type which includes the tokamak, stellerator, semi-stellerator and torsatron. Toroidal devices have the advantage of confining the plasma in closed magnetic field lines.
Among all magnetic confinement devices, the tokamak has progressed farthest toward commercial fusion reactor confinement parameters. The stellarator has shown itself to have the same or even greater potential. A number of detailed technical and economic problems beset these devices which have caused them to fall short of requirements. The tokamak has two basic disadvantages: (1) pulsed operation and (2) modest magnetic pressure to plasma pressure ratio (beta). Conventional stellarator and torsatron devices have the advantage of steady-state operation, but share the disadvantage of modest beta value, and introduce the additional disadvantages of difficult disassembly (due to the interlinking of the helical windings) and impaired particle orbits (due to the field assymetries associated with helical windings).
A device which combined the best features of the stellerator or torsatron and the tokamak using modular coils for easy disassembly, provided good confinement of particle orbits and had the ability to operate in a continuous steady-state low-aspect-ratio high-beta mode would constitute a significant advance in magnetic plasma confinement devices.